1. Technical Field
The present invention relates to a sample holder and a sample holder set each holding a sample thereon and being installed inside a measurement device such as a scanning electron microscope or a scanning probe microscope.
2. Description of the Related Art
There are various measurement devices (analyzer) that perform measurement based on different measurement principles. For example, a probe microscope uses a cantilever for measurement and can perform mapping of physical properties such as current, viscoelasticity, frictional force, and absorptivity as well as obtain information about sample's surface topography. A scanning electron microscope (SEM) uses an electron beam for measurement and can perform atom-mapping as well as analyze a sample's surface topography. An optical microscope, an optical coherence microscope, or a laser microscope uses a light beam or a laser for measurement and can analyze sample's surface topography.
In order to measure properties of an identical portion of a sample with various measurement devices that perform measurement based on different measurement principles, it is required to install a sample in a single complex measurement device in which various measurement devices are combined with each other. For example, Patent Document 1 discloses a technology by which an SEM and an optical lens column are arranged in a V-shaped pattern, a first measurement is performed on a portion of a sample by the SEM, and a second measurement is performed on the identical portion of the same sample by another measurement device. This device changes the direction of the sample using a tiling mechanism so that the surface of the sample is disposed to be perpendicular to axes of the SEM and the optical lens column.
However, the technology of Patent Document 1 has a problem that it is difficult to precisely align optical axes between different kinds of measurement devices, precision in the order of a micrometer. To be specific, there are two focal points on different observation axes (an optical axis of an SEM and an optical axis of an optical microscope), and it is very difficult to achieve a precise positional alignment of the focal points. Specifically, it is necessary to cross the two focal points within a range of micrometers and align the crossed focal points with an observation (measurement) point of the sample on which the observation (measurement) is performed. This is because, in an actual focusing process, a deviation from an ideal linear axis during a mechanical adjustment or a displacement of an observation axis occurs along an arc.
Furthermore, the device of Patent Document 1 can perform only two kinds of measurements (a measurement based on an SEM and a measurement based on an optical microscope). Therefore, when it is necessary to perform another kind of measurement apart from the measurements based on an SEM and an optical microscope, the device cannot meet the demand. In this case, it may be necessary to use a more complex measurement device equipped with an additional measurement device as well as an SEM and an optical microscope.